The protesters overturned vehicles, burned tyres, smashed shop windows and blocked traffic in the Bangladeshi capital's Mahakhali and Gulshan districts. Several people were injured with scores detained.

The protests were prompted by a government announcement that monthly minimum wages for the country's millions of garment workers would rise by about 80%. Union leaders say the raise is inadequate and does not match the high cost of living.

"We can't accept this raise," said Moshrefa Mishu, leader of the Garments Workers Unity Forum. "This is still very poor compared with the high cost of living. It's a betrayal."

Major high street retailers including Wal-Mart, Tesco, H&M, Zara, Carrefour, Gap, Metro, JCPenney, Marks & Spencer, Kohl's and Levi Strauss all import clothes in bulk from Bangladesh, which has some of the lowest labour costs in the world.

Although workers and labour rights groups had pressed for a monthly wage of 5,000 takas (£46), the new official minimum wage has been set at 3,000 takas a month. The previous monthly wage was set at 1,662 takas.

"We have tried our best to meet the demands of the workers," said labour minister Khandaker Mosharraf Hossain said, when announcing the new wages after months of talks with factory owners.

Bangladesh's garment exports, mainly to the US and Europe, earn more than $12bn (£7.6bn) a year, nearly 80%of the country's export income. The country has more than 4,000 factories employing between two and three million workers. Most of these are women, with many are working in hazardous conditions.

A report released last month by the International Trade Union Confederation (ITUC) in Vienna said Bangladeshi garment workers were the "world's most poorly paid", and that their exploitation was "on the rise".

The report cited a survey by the Bangladesh Factory Inspection Department, which showed that almost 15% of employers did not pay their workers on time. Many other factory owners did not pay overtime, while several continued to pay less than the minimum wage.

Mohammad Sohel, 21, a worker from Tejgaon, said: "I have been in service for the past eight years and have never protested before, despite the difficulties in living with such low pay. My pay is only 3,500 takas and my rent is 2,300 takas. What do I have after paying for somewhere to live?"

Another worker, Putul Begum, said: "We work to survive but ... commodity prices are going up and we cannot even arrange basic needs with our meagre income."

Campaigners in the UK calculated a living wage in Bangladesh at £98 a month. They claim western retailers could pay increased wages without raising prices.

"This would allow workers and their families to afford nutritious food, an education and healthcare," said Dominic Eagleton of ActionAid.

"The extra amounts needed are tiny – just 6p on a T-shirt, or 12p on a pair of jeans from Bangladesh. Retailers can afford to pay a living wage without hiking prices in shops."

The manufacturers say they are being squeezed by a slump in prices on the international market because of the global economic crisis. This, combined with higher production costs due to an energy crisis and poor infrastructure, are pushing them to the edge, they say.

Abdus Salam Murshedy, former president of Bangladesh Garment Manufacturers and Exporters Association, said many factory owners would be forced to close.

"The import cost of cotton and other raw materials have increased," he added.

The garment industry accounts for about 40% of Bangladesh's total industrial workforce. Low levels of unionisation and organisation have meant protests are chaotic and difficult for the police to predict and break up. Raids by protesters on well-known factories are frequent occurrences. Owners have hired their own gangs to protect their production lines.

In June, about 700 garment factories in a major industrial hub near Dhaka were shut for two days, after violent protests by tens of thousands of workers. Local journalists said the protests were expected to continue.